1. Field of the Invention
The present invention relates to a steering wheel equipped with an air bag system.
2. Description of the Prior Art
It is known to make a steering wheel containing an air bag system in the lower part of a pad section for absorbing an impact in the event of a collision of a motor vehicle.
In the above-noted air bag system a controller and an air bag inflator which triggers the air bag to inflate are located close to each other, for the purpose of making the structure of the system compact. Besides, the inflator and the air bag are adjacently located. Inside the controller of the air bag system is mounted an electronic circuit for detecting impacts of the motor vehicle and outputting a trigger signal to the inflator. The memory of this electronic circuit stores contents of an acceleration detecting process and a signal processing process by the electronic circuit from the detection of an impact caused by a collision of the motor vehicle to the production of a trigger signal for starting the inflator. Since the memory is constructed by a nonvolatile storage or is backed up by a battery, the contents processed by the electronic circuit will have been stored in the memory even after the air bag has been inflated.
After the air bag has been inflated, the memory of the electronic circuit is removed from the steering wheel. This memory can be connected to an external diagnosis device, whereby contents of the memory are read out for analysis of the operational state or the signal processing of the electronic circuit performed until a trigger signal is produced. Such an air bag, however, has a drawback that when this operation analysis of the electronic circuit is conducted after the inflation of the air bag, stored data in some cases can not be read.